Frame rates for different camera

The Red One camera shoots progressive. 23.97p, 24p, 25p, 30p are available when shooting at 4K. To shoot at faster speeds a drop in resolution is required. When shooting at 3K the camera can go to a maximum of 60p and at 2K it can go to 120p.

When altering the resolution the camera uses a smaller portion of the sensor (Windowing or cropping). The FOV of lenses is therefore altered when compared to shooting at 4K (See diagram below).

The Epic camera shoots up to 100fps at 5k
This increases to 300fps when we decrease our frame size to 2k

The Arri Alexa shoots 2k up to 60fps